This is a difficult and recurring question, and arises with regard to a wide range of privileges — lawyer-client, psychotherapist-patient, clergy-penitent, and more. It is particularly difficult when the conflict is with the constitutionally secured privilege against self-incrimination: A defendant argues that to properly defend himself he needs to have someone’s testimony (often a coconspirator’s), but that potential witness refuses to testify for fear of self-incrimination. And similar issues also arise with regard to so-called “rape shield” laws, which preclude the introduction of some kinds of evidence of the victim’s past sexual conduct.

For the most recent example of this, involving the relatively new “victim-advocate” privilege (which is intended as a variant of the psychotherapist-patient privilege for crime victims who go to specialized “victim advocate’ services rather than to traditional psychotherapists), see In re Subpoena to Crisis Connection, Inc. (Ind. Ct. App. July 15). The Indiana court canvasses the precedents from other states (which point in different directions), and holds that the Indiana victim-advocate privilege may have to yield to the defendant’s rights:

In Fromme‘s case, the trial court has already found that Fromme has met the particularity and materiality criteria, and Crisis Connection has not disputed those findings. The interest in privacy asserted by Crisis Connection, while important, is not strong enough to bar an in camera review of its records. Requiring defendants to meet the three-step test before obtaining an in camera review creates the proper balance between a criminal defendant‘s constitutional rights and an alleged victim‘s need for privacy. This approach is consistent with our decisions addressing other privileges and with the better-reasoned opinions of other jurisdictions. Therefore, we affirm the trial court‘s order.

“In camera” (“in-chambers”) review involves the judge looking at the records and deciding whether they were relevant enough to be disclosed.